This invention relates to support for the upper end of a ladder when the ladder is in use. More particularly, the invention is directed to a ladder support which is adaptable for use on different support surfaces.
A universal problem encountered when using a ladder is holding it in a stable position so that the upper end thereof does not slide to one side or the other when a person is climbing up or down on the ladder. Failure to properly secure the upper end of a ladder often results in serious injury to a person on the ladder if it slips sideways. Various attachments for securing the upper end of a ladder to different support services have been devised.
U.S. Pat. No. 4,765,439 to Kresmery and U.S. Pat. No. 5,279,389 to Crockett each disclose a mechanism for attaching the upper end of a ladder to a parapet wall.
U.S. Pat. No. 4,253,547 to Skaalen et al and U.S. Pat. No. 5,941,343 to Kelsey each disclose a mechanism for attaching the upper end of a ladder to the edge of a flat roof.
Patents which disclose devices for attaching or supporting the upper end of a ladder on a sloping roof include U.S. Pat. No. 4,723,632 to Gedgoudas et al; U.S. Pat. No. 4,949,810 to Dwinnell; U.S. Pat. No. 5,165,501 to Donnahey; U.S. Pat. No. 5,743,356 to Mitchell; U.S. Pat. No. 5,775,465 to Vossler; and U.S. Pat. No. 6,012,546 to Bee et al.
While all of these ladder support apparatuses are suitable for their intended purpose, each of them is only usable on one type of support structure. In other words, a support apparatus which is usable on a flat roof may not be used on a sloping roof or a parapet wall. Thus, every time the ladder is to supported on a different type of structure, a different support apparatus is needed.
In accordance with this invention, a multi-use support apparatus is provided for mounting on a support structure for supporting the upper end of a ladder having side rails and hollow tubular rungs. This support apparatus can be arranged in several different configurations for use with different support structures, such as parapet walls, flat roofs, sloping roofs and vertical beams or purlins. The support apparatus has a frame with a platform mounted on and supported thereby. A pair of spaced ladder support brackets mounted on the frame support the end of the ladder therebetween. A ladder attaching device extends through the upper rung of the ladder and is removably connected between the support brackets. The frame includes a pair of vertical rear supports attached to the platform, a pair of angular front supports attached to the platform, the vertical and angular supports both having upper ends extending above the platform and lower ends extending below the platform. Clamping devices are respectively and selectively attached to these lower ends for clamping or connecting to a parapet wall, a flat roof, a sloping roof and/or a vertical support member.
More particularly, the respective upper ends of the angular supports intersect with the upper ends of the respective vertical supports above the platform. The vertical supports have spaced lateral brackets for attachment to the support structure. The ladder support brackets each include a slot extending generally parallel to the annular supports and each having an upper end with an opening. The ladder attachment device includes a movable rod extending between the ladder support brackets and having threaded ends for receiving nuts for locking the rod in place in the slots of the ladder support brackets. The vertical supports and angular supports each have lower ends extending below the platform.
A clamping mechanism includes a first adjustable clamping device mounted adjacent the lower ends of the pair of vertical supports, which include a pair of extension arms slidably received in the lower ends of the respective vertical supports, each extension arm having a lower end with a transverse opening therethrough, a pair of latch devices for holding each respective extension arm in a selected vertical position within the respective vertical supports, and a pair of removable clamps extending through the respective transverse openings and mounted for movement inwardly for clamping engagement with a support structure and moving outwardly for release from the support structure.
The clamping mechanism also includes a second clamping device mounted adjacent the lower ends of the pair of angular supports. A clamp support is attached to the angular support and includes a pair of spaced vertical support struts which extend downwardly from the front of the platform, each having vertically spaced openings extending therethrough. The lower ends of the struts are interconnected by a lateral member. Also, the lower end of each strut is connected by a leg member to the lower end of respective angular supports. A second adjustable clamping device in the form of a pair of spaced clamps extends through spaced openings in the lateral member for movement inwardly for clamping engagement with a support structure and outwardly for release from the support structure.
In another configuration, the extension arms are removed from the vertical supports and inserted into the respective leg members so that the clamps can be moved toward and away from the platform for clamping to the edge of a flat roof.
In still another configuration, a pair of support bars each have a first end pivotally attached to an extension arm through the respective transverse openings and have a second end with a plurality of spaced first openings adjacent the second end thereof and extending therealong for attaching the support bars to a sloping roof. A positioning device is releasably connected through a selected opening in the pair of vertical struts and a selected first opening in the plurality of spaced first openings to position the respective support bars at a selected angle with respect to the vertical struts to correspond to the slope of the roof. Attaching elements extend through the spaced second openings for attaching the respective support bars to the roof.
In an additional configuration, the extension arms are slid upwardly into the lower ends of the respective vertical supports so that only the transverse opening is exposed. A pair of latch devices holds the respective extension arms in this selected vertical position. The transfers openings are arranged so that a first pair of removable clamps extend therethrough for moving inwardly into clamping engagement with a vertical support therebetween and movable outwardly for releasing from clamping engagement with the vertical support. The front end of the frame is supported on the upper rung of a ladder which is locked in a recess at the upper ends of the respective ladder support brackets.
From the foregoing discussion, advantages of this invention are readily apparent. A multi-purpose ladder support has been provided which can be selectively attached to a parapet wall, a flat roof and a sloping roof. Additional advantages of this invention will become apparent from the description which follows, taken in conjunction with the accompanying drawings.